I completely forgot about Adam the 2-humped camel who lives on the road between Petaluma and Tomales. I think he takes the prize.
I've been buzzed by vultures ("Not yet guys!").
Deer: I've seen 2 stags fighting their way across a relatively suburban road. I heard a commotion on the hill above me and stopped and there they were right out of Wild Kingdom. It was actually a little scary to be that close.
DH and I rescued a turtle from the middle of the road once.
I almost hit a 4 - 5 foot rattlesnake who was crossing Mines Road as I was descending Mt. Hamilton last summer.
We almost hit a skunk (living) at the beginning of the Mt. Tam Double last year. He was about to cross the road right in front of us. Now that would have been a miserable ride.